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A. MAGLAINE.

I PISTON FOR STEAM ENGINES. No. 373,936.

, Patented Nov. 29 1887.

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PISTON FOR STEAM ENGINES. No. 373,933. Patented Nov. 29, 1337.

UNITED STATES PATENT OFFICE.

ALEXANDER MAOLAINE, OF NO. 1 QUEENS ELMS, BELFAST, COUNTY OF ANTRIM,IRELAND.

PlS'l'ON FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 373,936, dated November29, 1887.

Application filed April 2, 18 7. Serial No. 233,430. (No model.)Patented in England August 30, 1886. No. 11,015; in Belgium January 31,1887, No. 75,922, and in France May 20. 1867, No. 180,765.

To all whom it may concern.-

Be it known that I, ALEXANDER MAO- LAINE, of N o. 1 Queens Elms,Belfast, in. the county of Antrim,Ireland,ship-owner, have invented newand useful Improvements in Pistons for Steam-Engines, (for which I havereceived Letters Patent in Great Britain and Ireland, No. 11,015, anddated the 30th day of August, 1886; in Belgium, No. 75,922, granted the31st day of January, 1887, and in France, No. 180,765, and granted theth day of May, 1887;) and I do hereby declare the nature of my inventionand in what manner the same is to be performed to be particularlydescribed and ascertained in and by the following statement.

This invention relates to metal packing rings for pistons of steam andother engines; and it consists, generically, in a metallic packing-ringadapted to fit a groove in the pistonhead or junk-ring thereof, andprovided with one or more springs which tend to expand the packing-ringcircumferentially, causing it to bear with equal force against theinterior of the cylinder, and thus render it steam-tight.

In the accompanying drawings, Figure 1 is a central sectional elevationof a piston-head having a junk-ring that is provided with groovesadapted to receive packing-rings embodying the present invention. Fig. 2is a horizontal section taken on the line a" x of Fig. 1, showing aportion of the piston-head. Figs. 3, 4, and 5 are enlargedcross-sectionsv taken, respectively, on the lines as, y, and vof Fig. 2.Fig. 6 is an enlarged elevation of a portion of the packing-ringadjacent to its meeting ends, looking from the inside of the ring andshowing one manner in which its circumferential expansion may beaccomplished. Fig. 7 is a partial elevation and a central section of apistonhead provided with the present improvements,the grooves beingprovided in the head instead of in ajunk-ring. Fig. 8 is a horizontalsection taken on the line as of Fig. 7, showing a portion of thepiston-head. Fig. 9 is an enlarged cross-section taken on the line 00 ofFig. 8, and Fig. 10 is an enlarged elevation of a portion of thepacking-ring adjacent to its meeting ends.

The present improvements comprehend the employment in a piston-head (orit may be in itsjunk-ring, when the latter is used, that is providedwith two or more circumferential grooves formed in and around theoutside of the piston-head or junk-ring) of a metallic packing-ring thatis expanded circumferentially outward against the inner surface ofthecylinder by means of a spring fitted at the ends of the packing-ring,where cut through, and arranged so as to press the ends apart and expandthe packing-ring circumferentially outward. This may also be effected bythe use of a series of springs, which may be employed supplementary tosaid spring or wholly alone.

The improvements also comprehend the employment, in combination with thecircumferentiallyexpanded packing-ring, of a separate tongue-pieceadapted to fit over the meeting ends of the divided packing-ring, so asto render it steam-tight.

The drawings illustrate two ways in which my invention may bepractically used, it being obvious that other forms may be employed toeffect the same result. 7

Referring now particularly to Figs. 1 to 6, inclusive, it is to beunderstood that a is the piston-body,and b the junk-ring thereof, of anyordinary construction. Thejunk-ring is provided with two or more groovesadapted to receive the metallic packing-ring d. The

. that it may be expanded andthus drawn over the piston-head orjunk-ring in getting it in its place in the groove. In order to renderthis packingring elastic, so that it will be caused to expandsufficiently to bear with sufficient pressure against the interiorsurface of the cylinder to render the piston steam-tight, I employ anexpanding-spring, e. As herein shown, this spring 6 surrounds a rod,f,the ends of which rod are secured in the packingring in the oppositeends of a recess formed equally in each of its meeting ends bysecuring-pins 9. Steel washers j may surround said rod f between theends of the recess and the spring for hearing the force of the springand preventing it from wearing upon the sides of the recess. The rod f,itis obvious, may be secured in the opposite sides of the recess by anyconvenient means. As herein shown, however, the packing-ring adjacent tothe recess is slotted at h to receive the ends of said red, one of whichends may be eyed, the securing-pin g passing through it. Its other end,however, is square, as shown in Fig. 4, and the securing-pin g securesit in place, so that it will have'longitudinal play in said slot, andthus permit the meeting ends of the packing-ring to separate. From thisit will be seen that the packingring being divided at the point a, andthe spring e bearing upon the opposite faces of the recess between saidmeeting ends, the tendency will be to force said ends apart and expandthe packing-ring circumferentially outward against the inner surface ofthe cylinder, and thus render the piston steamtight.

in order to prevent the leakage of steam past the meeting ends of thepacking-ring d as it is expanded outwardly, I provide a separatetongue-piece, 7c, of brass or other metal, (see Figs. 2 and 3,) that islet into a cut-away portion of the packing-ring directly over itsdivided portion a, and secured to one end of the packingring by smallpins at, so as to permit its ends to separate, and thus closing theopeningtherethrough. Thistongue-piece may be provided upon its lowerside with a pro jecting rib, p, entering a similar shaped grooved in thepacking ring d, to better confine the tongue-piece 7c in place. Thisobviates the danger of any sharp corners or pro jections occurring atsaid joint in the packingring to abrade or wear the interior surface ofthe cylinder.

As shown in Figs. 7 and 8, the packing-ring d, instead of being receivedin grooves formed in the junk-ring, the grooves are made directly in thepiston-body. The expansion of the packing-ring d may be effected in thesame manner as that before described by the spring e by the employmentofa series of coiled springs, 0, which may be employed supplementary tosaid spring e, to assist it in expanding the packing-ring outwardly oralone. As shown in Fig.8, the coiled spring 0 is dispensed with, and thepaekingring d expanded wholly by the series of springs 0 that arereceived in recesses formed at intervals in the piston-body in rear ofthe packing-ring, as is clearly shown. The tongue-piecek in thisinstance is similarly secured in a cut-away portion of the packing-ring,situated directly over the di vided portion at. Its rib 1), instead ofbeing a square one, as shown in Fig. 3, is an angular one, as best seenin Fig. 9, serving, however, the same purpose as that before described.

The mainspring 6, while shown as a coiled spring, may be of any formthat will effect the expansion of the packing-ring; and while thearrangement of the spring 6 as shown is the preferred one, any othermode of confining the spring to its seat so as to expand the ends of thepacking-ring may be employed. Thus, instead of a single rod. f, the sameobject will be effected by the use of a stud at each end of the recessso as to project into the coil of the spring, as is obvious. The springs0, also, instead of being coiled, as shown, may be any other form ofspring that will effect the expansion of the packingring. So, also, thethickness of the steel washers J, interposed between the ends of thespring 0 and the recess, may be of more or less thickness, so that theexpanding force of the spring may be varied, and thus the desired amountof pressure of the packingring against the surface of the cylinder behad.

I claim 1. The combination, with a piston-head, of a dividedpacking-ring received in a groove in said head, a spring insertedbetween the ends of the ring, adapted to expand it circumferentially,and a rod, f, surrounded by the spring, secured to one end of the ringby an eye, and being connected with the other end loosely, whereby ithas alongitudinal play as the ends of the ring approach or recede fromeach other, substantially as described.

2. The combination, with a piston-head, of a divided packing-ringreceived in a groove in said head, a spring or springs adapted to expandthe ring circumferentially, and a tongue-piece overlying the dividedends of the ring, it being secured to one end of the ring and lyingloosely against the other end of the ring, whereby the piece is held inplace, and also permits expansion and contraction of the ring,substantially as described.

3. The combination, with a piston-head, of a divided packing-ringsecured in a groove in said head, a spring or springs adapted to expandthe ring circumferentially, and atonguepiece overlying the divided endsof the ring and provided on its lower side with a projecting rib, p,entering a similar groove in the packing-ring to better confine it inplace, substantially as described.

In testimony whereof I havesigned my name to this specification in thepresence of two subscribing witnesses.

ALEXANDER MAOLAINE.

\Vitnesses:

HUGH HYNDMAN,

Belfast, Solicitor. JOHN D. CooKE.

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